EP3738891A1

EP3738891A1 - Landing platform for unmanned aerial vehicles

Info

Publication number: EP3738891A1
Application number: EP19382391.1A
Authority: EP
Inventors: Jesús Carlos Castellano Aldave; Jesús Villadangos Alonso; José Javier ASTRAIN ESCOLA
Original assignee: Fuvex Civil Sl
Current assignee: Fuvex Civil Sl
Priority date: 2019-05-17
Filing date: 2019-05-17
Publication date: 2020-11-18
Also published as: WO2020234177A1; US12208697B2; EP3969372C0; EP3969372B1; EP3969372A1; ES2956269T3; US20220315248A1

Abstract

The platform comprises supporting legs (12) fastened to the platform (10), and a control unit (13) and provides an electrical charging system including a plurality of coplanar adjacent electroconductive plates (14), with adjacent edges electrically insulated, arranged on an electrically insulated support. Each electroconductive plate (14) is connected by an electroconductive cable (15) to the control unit (13) and to a power source (16), wherein the electroconductive plate (14), electroconductive cable (15) and control unit (13) form an electrical circuit and the control unit (13) is configured to detect a change of an electric potential of the electrical circuit due to a UAV, landing on said platform and providing at least two points of contact with two different electroconductive plates (14). The platform supply energy, from power source to said two different electroconductive plates (14) using corresponding electroconductive cables (15) in order to charge powering means of said UAV.

Description

Technical field

The present invention discloses a landing platform for unmanned aerial vehicles, UAV, preferably vertical take-off and landing, VTOL, unmanned aerial vehicles.
The following terms or acronyms may be used throughout this document and should be understood as having the same connotations: "unmanned aerial vehicle", "UAV", "drone", "aerial vehicle", "aircraft" or "vehicle".

State of the Art

The use of unmanned aerial vehicles has increased exponentially in recent times for a wide variety of applications, such as security and surveillance and as a new way of delivering goods and/or correspondence.
However, seeing as weight is a key-factor in the design and optimal flight conditions for any kind of aerial vehicle, the powering means included in unmanned aerial vehicles are usually small in size, providing limited flight autonomy, in order to avoid the UAV becoming too cumbersome, and consequently they must be charged frequently if they are used continuously.
As such, the need has arisen for providing landing platforms that can be readily assembled in different locations and include a charging system so that the powering means, usually one or more batteries, of an unmanned aerial vehicle can be recharged.
EP 3045393 B1 discloses a portable device having at least one landing platform with multiple landing zones suitable for charging and housing VTOL unmanned aerial vehicles, said apparatus further including a sensory system made up of at least an array of LED/IR lamps to communicate and assist in automatically landing the unmanned aircraft on the landing platform. The sensory system may further include a phase array antenna, Lidar, a GPS or DGPS receiver, sonar or a beacon signal, amongst others. Each one of the landing zones includes a fixer to perform housing, charging and state data monitoring of the aircraft, once the aircraft has been connected to said fixer. A power supply is disposed in an outer peripheral portion of the landing zone.
US 9561871 B2 discloses an aerial vehicle docking system which includes a landing pad, having a concave landing surface and a central depression, and an aerial vehicle including landing gear (wheels or rollers) and a retractable protrusion which is shaped to mate with the central depression of the landing pad. The aerial vehicle docking system comprises a first induction coil included in the aerial vehicle and a second induction coil arranged in the landing pad, both coils being inductively coupled together and configured to transmit power wirelessly from the landing pad to the aerial vehicle when the protrusion of the aerial vehicle has mated with the depression of the landing pad, generating an electric current which is used to charge batteries of an unmanned aerial vehicle.
Patent application US 2017/217323 A1 describes a landing and take-off platform for unmanned aerial vehicles, specifically VTOL aerial vehicle, that includes a plurality of funnel-shaped centering housings that are configured to cooperate with an equivalent number of projections extending from a VTOL unmanned aerial vehicle, so that it lands in a predetermined position. The platform includes a mechanism, electrical contacts, for recharging a battery of the aerial vehicle and/or means for establishing a serial data transfer, when the vehicle is in said predetermined landing position.
However, all the cited prior art documents require the UAV or drone to land in a specific position or else include either conveying means or a coupling configuration in order to reposition the UAV once it has landed so it can be charged, and therefore the UAV must be in said particular position or coupling configuration in order to be charged.
The aim of the present invention is to provide a landing platform for unmanned aerial vehicles, which is both easy to transport and mount as it is made of detachable components, and providing a charging system which enables the UAV to land in any portion of the platform in order for it to be charged, and therefore eliminates the need for complex navigation and landing systems or the use of coupling or repositioning means.
Furthermore, the present invention includes supporting members which are capable of adapting to different terrains or locations in order to provide a substantially horizontal surface for the unmanned aerial vehicle to land and take-off adequately.

Brief description of the invention

The present invention discloses a landing platform for unmanned aerial vehicles (UAV), specifically vertical take-off and landing (VTOL) aircraft, the platform having a plurality of supporting legs (at least two of them length adjustable) fastened to an underside of the platform, in order to grant stability to the landing platform and provide a substantially horizontally flat surface for an unmanned aerial vehicle to land on, regardless of the terrain on which it is installed, and one or more signalling beacons, controlled by a control unit associated with the landing platform with ability to communicate wirelessly with a control unit or a transceiver of said unmanned aerial vehicle, said one or more signalling beacons configured to emit a homing signal to the UAV in order to guide it automatically towards the landing platform.
The landing platform disclosed herein further comprises an electrical charging system which comprises a plurality of adjacent and coplanar electroconductive plates, for example forming a matrix, with their adjacent edges electrically insulated, e.g. by dielectric separators arranged on an electrically insulated support (for example embedded in it) and with its face in side providing a landing surface. Each electroconductive plate is connected by an electroconductive cable to a control unit forming as a whole an electric circuit. The control unit if further connected to a power source intended to feed a battery of the UAV through those electroconductive cables. Therefore, each of the electroconductive plates provide an electric contact configured to cooperate with a corresponding positive electrical contact and with a corresponding negative electrical contact in at least one of projections of the UAV and connected to an electrical battery, when this vehicle lands on the platform. Thus, the landing area of the platform comprises a plurality of coplanar electro-insulated adjacent electrical contacts.
The control unit of the landing platform, cited previously, is configured to:

detect a change of an electric potential of said electric circuit due to an unmanned vehicle having land on the platform and establishing at least two points of contact by making an electrical contact of the vehicle with at least two different electroconductive plates, and
supply energy from said external power source to said at least two electroconductive plates (by means of a corresponding electroconductive cables), on which the UAV has landed, in order to charge powering means included in said UAV, such as one or more rechargeable batteries.

In addition, it is possible once a vehicle has landed on the platform at any time that the control unit carry out checks on the state of charge and electrical conditions of the vehicle.
While it has been indicated that each plate has an electroconductive cable to feed the UAV, it is possible to include more than one cable to perform separately functions of monitoring and charging.
According to a particular embodiment of the present invention, the platform is made up of a plurality of unitary modules coupled together, adjacent and coplanar to one another, with each unitary module comprising an electroconductive plate.
When the UAV lands on the platform and establishes two or more points of contact with at least two electroconductive plates, according to the number of structural support members (carrying an electrical contact) the UAV has, it is possible for one of these structural support members to land in a point contacting adjacent sides of two or more electroconductive plates. If this occurs, the control unit considers all electroconductive plates which are in contact with the structural support members of the UAV, as a single one in order to supply energy via one of the two electroconductive cables acting here as power cable provided.
In order to avoid short-circuits between projections or structural support members of the UAV (carrying an electrical contact) occurring in the event of two or more of these structural support members landing on the same electroconductive plate, one possible solution would be to design each one of the electroconductive plates, so that their maximum dimension in any direction is shorter than the distance between structural support members of a UAV.
The UAV, which is associated with and configured to land or take-off from the landing platform of the present invention, has an on-board electric circuit charging system which includes a protection device configured to protect and avoid discharging said powering means (e.g. one or more batteries) of the UAV in the event of a short-circuit, wherein said protection device is a combination of resistors and diodes to avoid current flow when a short-circuit occurs, and simultaneously enabling voltage readings under normal operating conditions, that is to say when no short-circuit occurs. Said on-board electric circuit charging system of the UAV is connected with the charging system of the landing platform, when operational.
The unitary modules may be designed in any shape, as long as it allows the platform to expand as much as desired by adding more unitary modules, whilst simultaneously remaining flat.
In order to achieve this, the unitary modules are preferably regular polygons, that is to say polygons which are equiangular and equilateral. Even more preferably, said regular polygons are selected from a group comprising: triangles, squares or hexagons, amongst others.
Following through with the previous embodiment, the disclosed landing platform preferably comprises a central module, made up of one or more unitary modules, having a total of n-sides (free edges), and at least n-secondary modules, with each one of the at least n-secondary modules being coupled to each one of the n-sides of the central module, wherein each one of the n-secondary modules is made up of one or more unitary modules.
It should be noted that the design or geometry of the unitary modules used to obtain the central module and the unitary modules used for the secondary modules may or may not be the same. Furthermore, the shapes or geometries obtained as a result of the combination of two or more unitary modules, which are regular polygons, does not have to meet with these requirements, and therefore the shape or geometry of either the central module or the secondary modules or both, do not necessarily have to form a regular polygon and therefore such a combination may enable the obtention of other shapes or geometries, such as convex quadrilaterals (e.g. an isosceles trapezium, rhombus, rectangle, amongst others).
Preferably, each one the n-secondary modules which are coupled to one of the n-sides of the central module have a signalling beacon on one of its external sides, said signalling beacon being configured to emit light signals, in a visible spectrum and/or an infrared spectrum, to said transceiver of a UAV.
Preferably, said plurality of supporting legs is fastened to the central module of the platform, wherein the plurality of supporting legs actually comprises at least one supporting leg with a fixed length, and two or more supporting legs with an adjustable length, said two or more supporting legs with an adjustable length being telescopic supporting legs that can be assisted by an actuator.
The following examples are used to illustrate the concepts discussed previously, and should be understood in a non-limiting manner:

Example 1

For this particular example, the unitary modules used are in the shape of squares, and both the central module and the secondary modules used are regular polygons.
The central module is a square made up of one unitary module, and therefore the number of sides "n" is 4. Therefore, the platform has at least four secondary modules, seeing as "n=4".
For this particular example, the platform actually uses eight secondary modules in order to provide a flat continuous quadrangular landing surface, wherein each one of the secondary modules is also made up of one unitary module, with four secondary modules coupled to each one of the sides of the central module, and the remaining four secondary modules being coupled to consecutive secondary modules and adjacent to a vertex of the central module.

Example 2

For this particular example, the unitary modules used are in the shape of equilateral triangles, and the central module is a regular polygon whilst the secondary modules are not.
In this case the central module is a hexagon made up of six unitary modules, and therefore the number of sides "n" is 6. Therefore, the platform has at least six secondary modules, seeing as "n=6".
For this particular example, the secondary modules are in the shape of an isosceles trapezium, each one consisting of three unitary modules coupled together, wherein the smaller side of each secondary module is coupled to a respective side of the central module.
It will be understood that references to geometric position, such as parallel, perpendicular, tangent, etc. allow deviations up to ± 5° from the theoretical position defined by this nomenclature.
It will also be understood that any range of values given may not be optimal in extreme values and may require adaptations of the invention to these extreme values are applicable, such adaptations being within reach of a skilled person.
Other features of the invention appear from the following detailed description of an embodiment.

Brief description of the Figures

The foregoing and other advantages and features will be more fully understood from the following detailed description of an embodiment with reference to the accompanying drawings, to be taken in an illustrative and not limitative, in which:

Fig. 1 is a perspective view illustrating an embodiment of a landing platform according to the present invention, that can constitute a central module of a larger platform.
Figs. 2 and 3 are a top plant view and a side view of the embodiment of Fig. 1.
Fig. 4 is a perspective view of a landing platform having a big extension and including a central module as the one in Fig. 1 and other secondary modules coupled to the n sides of the central module. In this Fig. it has been represented schematically the contact of two electrical contact of the vehicle with two of the plates of the platform.
Figs. 5 and 6 are a top plant view and a side view of the landing platform of Fig. 4.

Detailed description of an embodiment

As it can be seen in Fig. 1 the landing platform 10 of this invention includes supporting legs 12 fastened to the platform and having a fixed length and two additional legs 12a adjustable in length, for example including a telescopic feature, a motorised actuator 17 and a mechanism of extension -retraction.
The landing platform provides an electrical charging system comprising a plurality of coplanar adjacent electroconductive plates 14, with their adjacent or neighbouring edges electrically insulated, the plates 14 being arranged on an electrically insulated support (for example embedded in it), and with each electroconductive plate 14 being connected with one or more electroconductive cables 15 to a control unit 13 and (in general by means of this control unit 13) to a power source 16, so that the electroconductive plate 14, electroconductive cable/s 15 and control unit 13 form an electrical circuit. Power source can be installed near the landing platform 10 or at a distance thereof.
The control unit 13 is configured to for at least:

detect a change of an electric potential of said electrical circuit due to a UAV, landing on said platform 10 and providing at least two touch points of contact of electrical contacts of the UAV with at least two different electroconductive plates (14), and
supply energy, from said power source to said at least two electroconductive plates (14) using said electroconductive cables 15 (one for each of the plates 14) in order to charge powering means of said UAV.

The control unit 13 is further configured to perform operations to control the state of charge and electrical conditions of the UAV once the UAV has landed on the platform using said electroconductive cables 15 (one for each of the plates 14).
The landing platform as can be seen considering Figs. 1 and 4 is made up of a plurality of unitary modules coupled together, with each unitary module comprising an electroconductive plate 14, said unitary modules being adjacent and coplanar to one another.
In a general embodiment the platform 10 comprises:

a central module, made up of one or more unitary modules, having a total of n-sides, and
at least n-secondary modules, coupled to each one of the n-sides of the central module, wherein each one of the n-secondary modules is made up of one or more unitary modules.

According to the embodiment of Fig. 4 the landing platform 14 comprises

a hexagonal central module, made up of 6 unitary modules, and
secondary modules that are trapeziums made up of 3 unitary modules,

As it can be seen in Fig. 1, each of the n-edges of the central module includes a connecting socket 18 to establish an electrical connection with a corresponding adjacent plate 14 equipped in turn on its free edges of connecting sockets 18.
The central module receives on the underside a number of cables 15 equal to the number electroconductive plates 14 of the platform, and the other remaining cables are distributed to the peripheral sockets 18 of the n-edges of the central module. Thus, each of the central module electroconductive plates 14 is connected to a corresponding cable 15 and the other electroconductive plates 14 surrounding the central module receive the electrical connection with its corresponding cable 15 via one of the mentioned connecting sockets 18 facing each other on the adjacent edges.
In Fig. 4 the set of cables 15 have been indicated as single hose containing them by way of example.
Fig. 4 also shows that each of said n-secondary modules have a signalling beacon (11) at an external side configured to emit light signals to a UAV in a visible spectrum and/or an infrared spectrum. This light signal could be from any other part of the spectrum, e.g. UV.
According to a preferred embodiment the insulation of the adjacent edges of the electroconductive plates 14 is obtained by means of a dielectric sheet 19 arranged between the adjacent edges.
It should be noted that when it has been indicated that a cable 15 is provided for each electroconductive plate 14, this cable 15 may contain two separate and different lines, one for potential detection and the other for electrical power supply.
It will be understood that various parts of one embodiment of the invention can be freely combined with parts described in other embodiments, even being said combination not explicitly described, provided there is no harm in such combination.

Claims

A landing platform for unmanned aerial vehicles, UAV, having an electrical charging system, wherein said platform (10) comprises:
- a plurality of supporting legs (12) fastened to an underside of the platform (10), and

- a control unit (13),
characterised in that said electrical charging system comprises a plurality of coplanar adjacent electroconductive plates (14), with their adjacent edges electrically insulated, the electroconductive plates (14) being arranged on an electrically insulated support, with each electroconductive plate (14) being connected with at least an electroconductive cable (15) to said control unit (13) and to a power source (16), wherein said electroconductive plate (14), electroconductive cable (15) and control unit (13) form an electrical circuit and said control unit (13) is configured to for at least:
detect a change of an electric potential of said electrical circuit due to a UAV, landing on said platform and providing at least two points of contact by making electrical contact of the UAV with at least two different electroconductive plates (14), and

supply energy, from said power source to said at least two electroconductive plates (14) using said at least one corresponding electroconductive cable (15) of each of the two different electroconductive plates (14) in order to charge powering means of said UAV.
Landing platform according to claim 1, wherein the control unit (13) is further configured to perform operations to control the state of charge and electrical conditions of the UAV once the UAV has landed on the platform.
Landing platform according to claim 1, wherein the platform is made up of a plurality of unitary modules coupled together, with each unitary module comprising an electroconductive plate (14), said unitary modules being adjacent and coplanar to one another.
Landing platform according to claim 3, wherein the platform comprises:
- a central module, made up of one or more unitary modules, having a total of n-edges, and

- at least n-secondary modules, coupled to each one of the n-edges of the central module, wherein each one of the n-secondary modules is made up of one or more unitary modules.
Landing platform according to claim 4, wherein:
- said central module is a hexagon, made up of 6 unitary modules, and

- said n-secondary modules are trapeziums made up of 3 unitary modules,
wherein said unitary modules are equilateral triangles.
Landing platform according to claim 4, wherein each of the n-edges of the central module includes a connecting socket (18) to establish an electrical connection with a corresponding adjacent plate (14) equipped in turn on its free edges with connecting sockets (18).
Landing platform according to claim 6 wherein the central module receives on the underside a number of cables (15) equal to the number electroconductive plates (14) of the platform, each of the central module electroconductive plates (14) being connected to a corresponding cable (15), the remaining cables being distributed to peripheral sockets (18) of the n-edges of the central module, and the other electroconductive plates (14) surrounding the central module receive the electrical connection with a corresponding cable (15) via the mentioned connecting sockets(18).
Landing platform according to claim 4, wherein said plurality of supporting legs (12) are fastened to said central module of the platform (10).
Landing platform according to claim 1 or 8, wherein said plurality of supporting legs (12) comprises at least one supporting leg (12) with a fixed length, and two or more supporting legs (12a) with an adjustable length.
Landing platform according to claim 9, wherein said two or more supporting legs (12a) with an adjustable length are telescopic supporting legs and have an associated motor (17) and an extension-retraction mechanism.
Landing platform according to claim 4, wherein each of said n-secondary modules have a signalling beacon (11) at an external side configured to emit light signals to a UAV in at least a visible spectrum and/or an infrared spectrum.
Landing platform according to claim 3, wherein the plurality of unitary modules are regular polygons.
Landing platform according to claim 1, wherein the adjacent edges of the electroconductive plates (14) are electrically insulated by means of a dielectric sheet (19) arranged between said adjacent edges.